A monarchy in which the powers of the ruler are restricted to those granted under the constitution and laws of the nation. System of government in which a monarch (see monarchy) shares power with a constitutionally organized government. The monarch may be the de facto head of state or a purely ceremonial leader. The constitution allocates the rest of the government's power to the legislature and judiciary. Britain became a constitutional monarchy under the Whigs; other constitutional monarchies include Belgium, Cambodia, Jordan, The Netherlands, Norway, Spain, Sweden, and Thailand